The MySQL C API 编程实例

typedef struct st_mysql {
        

  NET           net;            /* Communication parameters */
        

  gptr          connector_fd;   /* ConnectorFd for SSL */
        

  char          *host,*user,*passwd,*unix_socket,
        

                *server_version,*host_info,*info,*db;
        

  unsigned int  port,client_flag,server_capabilities;
        

  unsigned int  protocol_version;
        

  unsigned int  field_count;
        

  unsigned int  server_status;
        

  unsigned long thread_id;      /* Id for connection in server */
        

  my_ulonglong affected_rows;
        

  my_ulonglong insert_id;       /* id if insert on table with NEXTNR */
        

  my_ulonglong extra_info;              /* Used by mysqlshow */
        

  unsigned long packet_length;
        

  enum mysql_status status;
        

  MYSQL_FIELD   *fields;
        

  MEM_ROOT      field_alloc;
        

  my_bool       free_me;        /* If free in mysql_close */
        

  my_bool       reconnect;      /* set to 1 if automatic reconnect */
        

  struct st_mysql_options options;
        

  char          scramble_buff[9];
        

  struct charset_info_st *charset;
        

  unsigned int  server_language;
        

} MYSQL;
        

typedef struct st_mysql_res {
        

  my_ulonglong row_count;
        

  unsigned int  field_count, current_field;
        

  MYSQL_FIELD   *fields;
        

  MYSQL_DATA    *data;
        

  MYSQL_ROWS    *data_cursor;
        

  MEM_ROOT      field_alloc;
        

  MYSQL_ROW     row;            /* If unbuffered read */
        

  MYSQL_ROW     current_row;    /* buffer to current row */
        

  unsigned long *lengths;       /* column lengths of current row */
        

  MYSQL         *handle;        /* for unbuffered reads */
        

  my_bool       eof;            /* Used my mysql_fetch_row */
        

} MYSQL_RES;
        

typedef char **MYSQL_ROW;
        

typedef struct st_mysql_field {
        

  char *name;                   /* Name of column */
        

  char *table;                  /* Table of column if column was a field */
        

  char *def;                    /* Default value (set by mysql_list_fields) */
        

  enum enum_field_types type;   /* Type of field. Se mysql_com.h for types */
        

  unsigned int length;          /* Width of column */
        

  unsigned int max_length;      /* Max width of selected set */
        

  unsigned int flags;           /* Div flags */
        

  unsigned int decimals;        /* Number of decimals in field */
        

} MYSQL_FIELD;
        

typedef unsigned long my_ulonglong;

printf (Number of rows: %lu/n”, (unsigned long) mysql_num_rows(result));

#include <mysql.h>
        

MYSQL mysql;
        

mysql_init(&mysql);
        

MYSQL *         STDCALL mysql_real_connect(MYSQL *mysql, const char *host,
         

                                           const char *user,
         

                                           const char *passwd,
         

                                           const char *db,
         

                                           unsigned int port,
         

                                           const char *unix_socket,
         

                                           unsigned int clientflag);
         

char *query;
        

int STDCALL mysql_real_query(MYSQL *mysql, const char *q, unsigned int length);
         

MYSQL_RES *res;
         

res = mysql_store_result(&mysql);
          

MYSQL_ROW STDCALL mysql_fetch_row(MYSQL_RES *result);
          

MYSQL_ROW row = mysql_fetch_row(res)
          

void mysql_free_result(MYSQL_RES *result)
        

mysql_close(&mysql);
        

Create Databse test
        

CREATE TABLE `t1` (

  `id` int(11) default NULL,

  `name` varchar(100) default NULL

)
        

/* testsql.c

  ** An example to use MYSQL C API

  ** Copyright 2004 Coon Xu.

  ** Author: Coon Xu

  ** Date: 
       
        05 Nov 2004
       

  */

   

  #include <mysql.h>

  #include <stdio.h>
        

int main(){

   MYSQL mysql;     // need a instance to init

   MYSQL_RES *res;

   MYSQL_ROW row;

   char *query;

   int t,r;
        

 // connect the database 

   mysql_init(&mysql);

   if (!mysql_real_connect(&mysql,"localhost", "mmim", "mmim", "test",0,NULL,0))

   {

       printf( "Error connecting to database: %s/n",mysql_error(&mysql));

   }

   else printf("Connected.../n");
        

 // get the result from the executing select query

 query = "select * from t1";

   

 t = mysql_real_query(&mysql,query,(unsigned int) strlen(query));

 if (t)

 {

    printf("Error making query: %s/n",

      mysql_error(&mysql));

 }

 else printf("[%s] made.../n", query); 
        

 res = mysql_store_result(&mysql); 
        

 while(row = mysql_fetch_row(res))

 {

  for(t=0;t<mysql_num_fields(res);t++)

  {

   printf("%s ",row[t]);

  }

  printf("/n");

 }

 

 printf("mysql_free_result.../n");

 mysql_free_result(res);     //free result after you get the result

 

 sleep(1);    

 

 // execute the insert query

 query = "insert into t1(id, name) values(3, 'kunp')";

 t = mysql_real_query(&mysql,query,(unsigned int) strlen(query));

 if (t)

 {

    printf("Error making query: %s/n",

      mysql_error(&mysql));

 }

 else printf("[%s] made.../n", query); 

   

    mysql_close(&mysql);

   

   return 0;

}
        

gcc testsql.c -I/usr/include/mysql -L/usr/lib/mysql -lmysqlclient